Coating machine



1945 E. NORDSTROM ETAL 2,375,312

COATING MACHINE Filed Oct. 5, 1941 2 Sheets-Sheet 1 INVENTOR.

Z jjmi' W ATTQENEYS E. NORDSTROM ETAL 2,375,812

COATING MACHINE Filed Oct. 5, 1941 2 Sheets-Sheet 2 Patented May 15,1945 Grover, Maplewood, N. J assignors to American Can Company, NewYork, N. Y., a corporation of New Jersey Application October 3, 1941,Serial No. 413,522

1 Claim.

The present invention relates to a coating machine having a roller and adoctor blade for applying a film of fluid coating substance to a web ofmaterial passed over the roller and has particular reference to heatingthe doctor blade to facilitate application of the coating substance tothe web.

In the manufacture of certain containers such as those made of fibre andthe like, a coating substance is sometimes applied in a design orpredetermined configuration to the flat stock or web from which thecontainersare made. In such container or can making practice the coatingsubstance is usually applied by an intaglio roller which rotates in abath of the coating substance. The rotating roller picks up the coatingsubstance and a doctor blade which bears against the roller scrapes offall the substance excepting that which is disposed in the intagliopockets or recesses of the roller. It is this retained coating substancethat is applied to the web of container material.

Some coating substances may be heated to maintain them in a fluidcondition while being applied to the web of material. In order tofacilitate the application of such coating substances the instantinvention contemplates heating the doctor blade so that the coatingsubstance scraped oil the roller will be prevented from being chilledand thereby will be prevented from adhering to the blade.

An object therefore of the invention is the provision of a coatingmachine having an intaglio applying roller and a doctor blade whereinthe doctor blade is heated to maintain in a liquid condition the coatingsubstance scraped oil. the roller so that the coating substance will beprevented from adhering to the blade.

Numerous other objects and advantages of the invention will be apparentas it is better understood from the following, description, which, takenin connection with theaccompanying drawings, discloses a preferredembodiment thereof.

Referring to the drawings:

Figure 1 is a longitudinal section through a coating machine embodyingthe instant invention;

Fig. 2 is a transverse section taken substantially along the line 2-2 inFig. 1;

Fig. 3 is a view similar to Fig. 2 showing the doctor blade on anenlarged scale, with parts broken away and shown in section;

Fig. 4 is a top plan view of the doctor blade shown in Fig. 3, withparts broken away: and

Fig. 5 is a transverse section taken substantially along the line 5-5 inFig. 3.

As a preferred embodiment of the invention the drawings illustrate acoating machine in which a strip A (Fig. 1) of web material, such asfibre or the like, is imprinted preferably with a thermoplastic adhesiveapplied in a desired pattern as the web is advanced through the machine.The strip or web may-be substantially continuous and may be fed into andaway from the machine in any suitable manner.

I and rotates in a bath of heated thermoplastic ad- While in themachine. the web is fed by upper and lower cooperating rollers betweenwhich the web passes. These rollers constitute an adhesive applyingroller N (Fig. l) and a pressure roller l2. The pressure roller l2presses the moving web against the applying roller Ii. During its travelthrough the machine the web is held taut by an idler roller l8.

The applying roller H preferably is hollow so that a fluid heatingmedium such as steam, hot water, hot oil or the like may be circulatedtherethrough if desired to maintain the roller in a heated condition.This roller together with the pressure roller 12 are formed withtrunnions which are journaled in suitable hearings in a pair of sideframes 15 which constitute the main frame of the machine. The idlerroller i8 is supported on a shaft i6 which is carried in the machineframes IB.

The applying roller II is of intaglio character hesive maintained in aliquid condition in an open top tank, receptacle or reservoir l8. Thetank is located between the machine side frames it. The

bottom of the tank is formed with a heatin chamber I! through which asuitable heatin medium such as steam, hot water, hot oil, or the like iscirculated by way of inlet and outlet pipes 20, 2| to maintain theadhesive in the tank in a liquid condition.

As the applying roller rotates in the bath oi thermoplastic adhesive, aquantity of the adhesive is picked up by the roller and carried towardthe web. All of this picked up adhesive except that contained within thepockets or intaglio recesses of the roller is scraped off by a doctorblade 22 having a wiping edge which bears upon the periphery of theintaglio roller. It is this retained adhesive that is applied to themoving web in the pattern laid out on the surface of the intaglioroller.

The doctor blade 22 extends across the machine and is located in thetank l8 above the bath, of liquid adhesive contained therein. The

blade is secured to a spacer block 25 (Figs. 4 and 5) which in turn isfastened by screws 28 to a base 21 of a movable carriage generallyindicated by the numeral 28. At each end, the carriage merges into aninverted U-shaped arm 32 (Figs. 2 and 3) which extends up out of thetank, over the top, and down adjacent the outside wall of the tank. Atthe outer terminal ends, the arms are formed with trunnions 33 which arecarried in the inner ends of a pair of swing arms 34 (Figs. 1 and 5).The outer ends of the swing arms are mounted on a stationary pivot shaft35 which is carried in suitable bearings formed in the machine framesl5.

When the doctor blade 22 is in its normal operating position in contactwith the intaglio roller H, the swing arms 34 are held down by bolts 36which are threaded into bosses 31 on the machine frames l5. This holdsthe carriage 28 against vertical movement. When it is desired to removethe carriage and blade from the tank, the bolts are loosened or takenout and the unit thereupon may be swung upwardly and outwardly with theswing arms 34 rocking on the pivot shaft 35.

Provision is made for heating the doctor blade 22, as hereinbeforementioned. This is brought about by a pair of electric heating elements4| (Figs. 3, 4 and 5) which are imbedded in a rapid heat conductor, suchas aluminum packing 42, disposed in longitudinal grooves 43 in thespacer block 25. The ends of the heating elements project out from theends of the spacerv block 25 and extend up alongside the U-shaped arms32 where they terminate in electric inlet and outlet boxes 45. There aretwo of these boxes and they are secured to the top of the arms.

Inside the boxes 45, the heating elements connect with lead wires 46,41, 48, 49 which lead to and from any suitable source of electricenergy.

Itis this electric energy that flows through the heating elements 4| andthereby creates sumcient heat in the spacer block 25 to maintain thedoctor blade 22 at a desirable elevated temperature.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description, and it will beapparent that various changes may be made in the form, construction andarrangement of the parts without departing from the spirit and scope ofthe invention or sacrificing all of its material advantages, the formhereinbefore described being merely a preferred-embodiment thereof.

We claim:

In a machine for applying adhesive in fluid form to web material, thecombination of a receptacle for the adhesive, mounted in the receptaclefor removing adhesive therefrom and applying it to the web of materialpassed over said roller, a doctor blade unit movably mounted in saidreceptacle including a carriage mounted for pivotal movement relative tothe receptacle and a doctor blade on said carriage having its wipingedge bearing against the surface of said roller for scraping surplusadhesive therefrom, an elongated electrical heating element disposedadjacent and extending longitudinally of said doctor blade formaintaining the latter at a desirable elevated temperature, said heatingelement being completely encased within a heat conducting metallicmaterial for rapidly transmitting heat from said element to the wipingedge of the doctor blade, and electrical inlet and outlet boxesrespectively mounted on opposite ends of said pivotally mounted carriagefor housing means for conducting electrical energy to and from oppositeends of said completely encased elongated heating element.

ELOF NORDS'IROM. VICTOR T. GROVER- a roller rotatably-

